Method and apparatus for forming matching tapered surfaces on interfitting male and female parts

Abstract

Matching tapered surfaces are cut on male and female parts to be interfitted along the tapered surfaces by utilizing a lathe, having a motor driven tail stock opposite a conventional head stock, with the tail stock being mounted relative to the bed of the lathe for adjustable movement to position the tail stock at a desired taper angle relative to the longitudinal centerline of the lathe. The tail stock is equipped with a "direct mounting" chuck having jaws for holding the parts during the taper cutting operation. In one operation, the male part, which is hollow, is gripped internally thereof by the tail stock chuck, and the taper is cut on the external surface of the part by movement of the cutting tool in a horizontal plane parallel to the centerline of the lathe. Since the tail stock has been preset at the desired tapered angle, the external surface of the male part will be cut with the desired taper. The male part is then removed from the chuck and then the female part is mounted on the chuck of the tail stock by engaging the jaws of the chuck on the external surface of the female part. The cutting tool is then moved in a horizontal plane to enter the internal passage of the female part and to cut the taper along the internal surface thereof. Since the angular setting of the tail stock remains the same as that previously set for cutting the male part, the internal taper cut on the female part will exactly correspond to the male part so that when these parts are ultimately fitted together, there should be substantial contact between the tapered surfaces thereof.

What is claimed is: 
     
       1. A method of forming matching tapered surfaces on male and female parts to be interfitted one within the other along the complementary tapered surfaces thereof, the method comprising the steps of; mounting the female part on the chuck of a lathe with the chuck axis extending at an angle to a longitudinal centerline of the lathe, cutting the internal surface of the female part to provide a tapered surface by moving a cutting tool of the lathe within a passage of the female part along a line parallel to the centerline of the lathe, removing the female part from the chuck, mounting the male part of the chuck without changing the angular position of the chuck relative to the centerline of the lathe, and without changing the angular position of the cutting tool relative to the centerline of the lathe, cutting the external surface of the male part by moving the same cutting tool of the lathe along a path parallel to the centerline of the lathe, and wherein the rotation of the chuck and the male part held therein during the cutting of the taper on the male part is reversed relative to the rotation of the chuck and the female part during the cutting of the taper on the female part. 
     
     
       2. The method defined in claim 1 including the step of gripping the female part with the chuck by engaging an external surface portion of the female part with jaws of the chuck. 
     
     
       3. The method defined in claim 2 applied to a male part having an internal passage, the method further comprising the step of gripping the male part with the chuck by engaging internal surfaces of the male part within the passage of the male part with the jaws of the chuck. 
     
     
       4. The method defined in claim 1 wherein there is utilized a lathe having a motor driven tail stock including said chuck and which is capable of adjustment about a vertical axis to position the parts at said angle relative to said centerline of the lathe. 
     
     
       5. The method defined in claim 1 wherein the female part is a sleeve to be included in a cooler assembly for a die and wherein the male part is a hollow die used in continuous vertical casting of bar products. 
     
     
       6. In a lathe having a longitudinal centerline and a head stock for driving a chuck to be mounted to the head stock with the chuck rotatable about said centerline of the lathe, a bed having guide rails parallel to the centerline of the lathe, and a tool carriage mounted on the guide rails of the bed and having means for mounting a cutting tool relative to the carriage in a desired position relative to the centerline of the lathe; the improvement comprising a tail stock having a rotatable chuck driving shaft extending in a horiztonal plane, means mounting the tail stock on the bed rails of the lathe for adjustable movement about a vertical axis to place said shaft at a desired angle relative to the centerline of the lathe, and means including a reversible variable speed motor for driving the shaft in rotation for driving a chuck to be mounted on the shaft, means for moving the tail stock along the bed into any one of a plurality of preselected positions, said tail stock including a base mounted to said guide rails of the bed, and a swivel mounted on the base for rotating the tail stock about a vertical axis relative to said base, and means for locking the swivel in an adjusted rotated position.